#include <userver/utest/assert_macros.hpp>

#include <unordered_map>

#include <userver/compiler/demangle.hpp>
#include <userver/formats/json/parser/parser.hpp>
#include <userver/formats/json/serialize.hpp>

// NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
#define EXPECT_THROW_TEXT(code, exception_type, exc_text) UEXPECT_THROW_MSG(code, exception_type, exc_text)

USERVER_NAMESPACE_BEGIN
namespace fjp = formats::json::parser;

TEST(JsonStringParser, Int64) {
    const std::string input{"12345"};

    int64_t result{0};
    fjp::Int64Parser int_parser;
    fjp::SubscriberSink<int64_t> sink(result);
    int_parser.Subscribe(sink);
    int_parser.Reset();

    fjp::ParserState state;
    state.PushParser(int_parser);
    state.ProcessInput(input);

    EXPECT_EQ(result, 12345);

    EXPECT_EQ((fjp::ParseToType<int, fjp::IntParser>("3.0")), 3);

    EXPECT_EQ((fjp::ParseToType<int, fjp::IntParser>("0.0")), 0);
    EXPECT_EQ((fjp::ParseToType<int, fjp::IntParser>("0")), 0);

    EXPECT_EQ((fjp::ParseToType<int, fjp::IntParser>("-3.0")), -3);
    EXPECT_EQ((fjp::ParseToType<int, fjp::IntParser>("-3")), -3);
    EXPECT_EQ((fjp::ParseToType<int, fjp::IntParser>("-1192.0")), -1192);

    EXPECT_THROW_TEXT(
        (fjp::ParseToType<int, fjp::IntParser>("3.01")),
        fjp::ParseError,
        "Parse error at pos 4, path '': integer was expected, but "
        "double found, the latest token was 3.01"
    );
}

TEST(JsonStringParser, Double) {
    EXPECT_DOUBLE_EQ((fjp::ParseToType<double, fjp::DoubleParser>("1.23")), 1.23);
    EXPECT_DOUBLE_EQ((fjp::ParseToType<double, fjp::DoubleParser>("-20")), -20.0);
    EXPECT_DOUBLE_EQ((fjp::ParseToType<double, fjp::DoubleParser>("0")), 0);
    EXPECT_DOUBLE_EQ((fjp::ParseToType<double, fjp::DoubleParser>("123.456")), 123.456);

    EXPECT_THROW_TEXT(
        (fjp::ParseToType<double, fjp::DoubleParser>("123.456a")),
        fjp::ParseError,
        "Parse error at pos 7, path '': The document root must not "
        "be followed by other values."
    );
    EXPECT_THROW_TEXT(
        (fjp::ParseToType<double, fjp::DoubleParser>("[]")),
        fjp::ParseError,
        "Parse error at pos 0, path '': number was expected, but array found"
    );
    EXPECT_THROW_TEXT(
        (fjp::ParseToType<double, fjp::DoubleParser>("{}")),
        fjp::ParseError,
        "Parse error at pos 0, path '': number was expected, but object found"
    );
}

TEST(JsonStringParser, DoublePrecision) {
    static_assert(56.411117000000004 != 56.411117);
    constexpr auto kPreciseDoubleString = "56.411117000000004";
    EXPECT_EQ(fmt::to_string(fjp::ParseToType<double, fjp::DoubleParser>(kPreciseDoubleString)), kPreciseDoubleString);
}

TEST(JsonStringParser, Int64Overflow) {
    std::string input{std::to_string(-1ULL)};

    EXPECT_THROW_TEXT(
        (fjp::ParseToType<int64_t, fjp::Int64Parser>(input)),
        fjp::ParseError,
        fmt::format(
            "Parse error at pos 20, path '': Failed to convert {} 18446744073709551615 into {} "
            "due to positive integer overflow, the latest token was 18446744073709551615",
            compiler::GetTypeName<std::uint64_t>(),
            compiler::GetTypeName<std::int64_t>()
        )
    );
}

class EmptyObjectParser final : public fjp::BaseParser {
protected:
    void StartObject() override {}

    void EndObject() override { parser_state_->PopMe(*this); }

    std::string Expected() const override { return "'}'"; }
    std::string GetPathItem() const override { return {}; }
};

TEST(JsonStringParser, EmptyObject) {
    const std::string input{"{}"};

    EmptyObjectParser obj_parser;

    fjp::ParserState state;
    state.PushParser(obj_parser);
    EXPECT_NO_THROW(state.ProcessInput(input));
}

TEST(JsonStringParser, EmptyObjectKey) {
    std::string input{"{\"key\":1}"};

    EmptyObjectParser obj_parser;

    fjp::ParserState state;
    state.PushParser(obj_parser);
    EXPECT_THROW_TEXT(
        state.ProcessInput(input),
        fjp::ParseError,
        "Parse error at pos 6, path '': '}' was "
        "expected, but field 'key' found, the latest token was \"key\""
    );
}

struct IntObject final {
    int64_t field{0};
};

bool operator==(const IntObject& lh, const IntObject& rh) { return lh.field == rh.field; }

class IntObjectParser final : public fjp::TypedParser<IntObject> {
public:
    void Reset() override { has_field_ = false; }

protected:
    void StartObject() override {}

    void Key(std::string_view key) override {
        if (key == "field") {
            key_ = key;
            has_field_ = true;
            field_parser_.Reset();
            field_parser_.Subscribe(field_sink_);
            parser_state_->PushParser(field_parser_);
        } else {
            throw fjp::InternalParseError("Bad field for IntObject ('" + std::string(key) + ")");
        }
    }

    void EndObject() override {
        if (!has_field_) {
            throw fjp::InternalParseError("Missing required field 'field'");
        }
        SetResult(std::move(result_));
    }

    // Note: not strictly correct
    std::string Expected() const override { return "'{'"; }

    std::string GetPathItem() const override { return key_; }

private:
    IntObject result_;
    fjp::Int64Parser field_parser_;
    std::string key_;
    fjp::SubscriberSink<int64_t> field_sink_{result_.field};
    bool has_field_{false};
};

TEST(JsonStringParser, IntObject) {
    const std::string input("{\"field\": 234}");
    EXPECT_EQ((fjp::ParseToType<IntObject, IntObjectParser>(input)), IntObject({234}));
}

TEST(JsonStringParser, IntObjectNoField) {
    std::string input("{}");

    EXPECT_THROW_TEXT(
        (fjp::ParseToType<IntObject, IntObjectParser>(input)),
        fjp::ParseError,
        "Parse error at pos 1, path '': Missing required field 'field'"
    );
}

TEST(JsonStringParser, ArrayIntObjectNoField) {
    std::string input("[{}]");

    IntObjectParser obj_parser;
    fjp::ArrayParser<IntObject, IntObjectParser> array_parser(obj_parser);

    std::vector<IntObject> result;
    fjp::SubscriberSink<decltype(result)> sink(result);
    array_parser.Reset();
    array_parser.Subscribe(sink);
    fjp::ParserState state;
    state.PushParser(array_parser);

    EXPECT_THROW_TEXT(
        state.ProcessInput(input), fjp::ParseError, "Parse error at pos 2, path '[0]': Missing required field 'field'"
    );
}

TEST(JsonStringParser, ArrayIntErrorMsg) {
    fjp::IntParser obj_parser;
    fjp::ArrayParser<int, fjp::IntParser> array_parser(obj_parser);

    std::vector<int> result;
    fjp::SubscriberSink<decltype(result)> sink(result);
    array_parser.Reset();
    array_parser.Subscribe(sink);
    fjp::ParserState state;
    state.PushParser(array_parser);

    EXPECT_THROW_TEXT(
        state.ProcessInput("1"),
        fjp::ParseError,
        "Parse error at pos 1, path '': array was expected, but "
        "integer found, the latest token was 1"
    );
}

TEST(JsonStringParser, ArrayInt) {
    const std::string input("[1,2,3]");
    std::vector<int64_t> result{};

    fjp::Int64Parser int_parser;
    fjp::ArrayParser<int64_t, fjp::Int64Parser> parser(int_parser);
    fjp::SubscriberSink<decltype(result)> sink(result);
    parser.Reset();
    parser.Subscribe(sink);

    fjp::ParserState state;
    state.PushParser(parser);
    state.ProcessInput(input);
    EXPECT_EQ(result, (std::vector<int64_t>{1, 2, 3}));
}

TEST(JsonStringParser, ArrayArrayInt) {
    const std::string input("[[1],[],[2,3,4]]");
    std::vector<std::vector<int64_t>> result{};

    fjp::Int64Parser int_parser;
    using Subparser = fjp::ArrayParser<int64_t, fjp::Int64Parser>;
    Subparser subparser(int_parser);
    fjp::ArrayParser<std::vector<int64_t>, Subparser> parser(subparser);
    fjp::SubscriberSink<decltype(result)> sink(result);
    parser.Reset();
    parser.Subscribe(sink);

    fjp::ParserState state;
    state.PushParser(parser);
    state.ProcessInput(input);
    EXPECT_EQ(result, (std::vector<std::vector<int64_t>>{{1}, {}, {2, 3, 4}}));
}

TEST(JsonStringParser, ArrayBool) {
    const std::string input{"[true, false, true]"};
    std::vector<bool> result;

#if defined(__GNUC__) && !defined(__clang__) && __GNUC__ <= 9
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Warray-bounds"  // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59124
#endif

    fjp::BoolParser bool_parser;
    fjp::ArrayParser<bool, fjp::BoolParser> parser(bool_parser);
    fjp::SubscriberSink<decltype(result)> sink(result);
    parser.Reset();
    parser.Subscribe(sink);

    fjp::ParserState state;
    state.PushParser(parser);
    state.ProcessInput(input);
    EXPECT_EQ(result, (std::vector<bool>{true, false, true}));

#if defined(__GNUC__) && !defined(__clang__) && __GNUC__ <= 9
#pragma GCC diagnostic pop
#endif
}

template <class T>
struct JsonStringParserMap : public ::testing::Test {
    using Map = T;
};

using Maps = ::testing::Types<std::map<std::string, int>, std::unordered_map<std::string, int>>;
TYPED_TEST_SUITE(JsonStringParserMap, Maps);

TYPED_TEST(JsonStringParserMap, Map) {
    using Map = typename TestFixture::Map;

    fjp::IntParser int_parser;
    fjp::MapParser<Map, fjp::IntParser> parser{int_parser};

    Map result;
    fjp::SubscriberSink<decltype(result)> sink(result);
    parser.Reset();
    parser.Subscribe(sink);
    fjp::ParserState state;
    state.PushParser(parser);
    state.ProcessInput(R"({"key": 1, "other": 3})");
    EXPECT_EQ(result, (Map{{"key", 1}, {"other", 3}}));
}

TYPED_TEST(JsonStringParserMap, Empty) {
    using Map = typename TestFixture::Map;

    fjp::IntParser int_parser;
    fjp::MapParser<Map, fjp::IntParser> parser{int_parser};

    Map result;
    fjp::SubscriberSink<decltype(result)> sink(result);
    parser.Reset();
    parser.Subscribe(sink);
    fjp::ParserState state;
    state.PushParser(parser);
    state.ProcessInput(R"({})");
    EXPECT_EQ(result, (Map{}));
}

TYPED_TEST(JsonStringParserMap, Invalid) {
    using Map = typename TestFixture::Map;

    fjp::IntParser int_parser;
    fjp::MapParser<Map, fjp::IntParser> parser{int_parser};

    Map result;
    fjp::SubscriberSink<decltype(result)> sink(result);
    parser.Reset();
    parser.Subscribe(sink);
    fjp::ParserState state;
    state.PushParser(parser);

    EXPECT_THROW_TEXT(
        state.ProcessInput(R"(123)"),
        fjp::ParseError,
        "Parse error at pos 3, path '': object was expected, but "
        "integer found, the latest token was 123"
    );

    EXPECT_THROW_TEXT(
        state.ProcessInput(R"({{"key": 1}})"),
        fjp::ParseError,
        "Parse error at pos 1, path '': Missing a name for object member."
    );

    EXPECT_THROW_TEXT(
        state.ProcessInput(R"(}{)"), fjp::ParseError, "Parse error at pos 0, path '': The document is empty."
    );
}

TEST(JsonStringParser, JsonValue) {
    const std::string inputs[] = {
        R"([1, "123", "", -2, 3.5, {"key": 1, "other": {"key2": 2}}, {}])",
        R"({})",
    };
    for (const auto& input : inputs) {
        auto value_str = formats::json::FromString(input);
        auto value_sax = fjp::ParseToType<formats::json::Value, fjp::JsonValueParser>(input);
        EXPECT_EQ(value_str, value_sax) << "input: " + input + ", str='" + ToString(value_str) + "', sax='" +
                                               ToString(value_sax) + "'";
    }
}

namespace {
std::string GenerateNestedJson(std::size_t depth) {
    std::string result{};
    result.reserve(depth * 8);

    for (std::size_t i = 0; i < depth; ++i) {
        result.append("{\"o\":");
    }
    result.append("{}");
    for (std::size_t i = 0; i < depth; ++i) {
        result.push_back('}');
        if (i + 2 == depth) {
            result.append(",\"nonsense\"");
        }
    }

    return result;
}
}  // namespace

TEST(JsonStringParser, JsonValueDepth) {
    const auto input = GenerateNestedJson(formats::json::kDepthParseLimit + 1);

    for (std::size_t i = 1; i <= 100; ++i) {
        UEXPECT_THROW_MSG(
            (fjp::ParseToType<formats::json::Value, fjp::JsonValueParser>(input)),
            formats::json::parser::BaseError,
            "Exceeded maximum allowed JSON depth of: 128"
        );
    }
}

TEST(JsonStringParser, JsonValueLeak) {
    const auto input = GenerateNestedJson(formats::json::kDepthParseLimit - 2);

    for (std::size_t i = 1; i <= 100; ++i) {
        UEXPECT_THROW_MSG(
            (fjp::ParseToType<formats::json::Value, fjp::JsonValueParser>(input)),
            formats::json::parser::ParseError,
            "Missing a colon after a name of object member."
        );
    }
}

TEST(JsonStringParser, JsonValueBad) {
    const std::string inputs[] = {
        R"({)",         //
        R"()",          //
        R"({}})",       //
        R"(})",         //
        R"({"key")",    //
        R"({"key)",     //
        R"({"key":1)",  //
        R"([)",         //
        R"(1 2)",       //
    };
    for (const auto& input : inputs) {
        EXPECT_THROW((fjp::ParseToType<formats::json::Value, fjp::JsonValueParser>(input)), fjp::ParseError);
    }
}

TEST(JsonStringParser, BomSymbol) {
    const std::string input =
        "{\r\n\"track_id\": \"0000436301831\",\r\n\"service\": "
        "\"boxberry\",\r\n\"status\": \"pickedup\"\r\n}";
    auto value_str = formats::json::FromString(input);
    auto value_sax = fjp::ParseToType<formats::json::Value, fjp::JsonValueParser>(input);
    EXPECT_EQ(value_str, value_sax);
}

TEST(JsonStringParser, ZeroByte) {
    EXPECT_THROW_TEXT(
        (fjp::ParseToType<formats::json::Value, fjp::JsonValueParser>(std::string_view{"{}\0z", 4})),
        formats::json::parser::BaseError,
        "Parse error at pos 2, path '': The document root must not be followed by other values."
    );
}

USERVER_NAMESPACE_END
